I am a bit worried about that patch as it adds a completely pointless set of brackets in a couple of places. If I see
if (( ... )) {
my natural reaction is to wonder if they are placed correctly, and on my quick reading of the logic I think my suspicions are justified! Does the code look right to you?

(In reply to Michael Young from comment #2)
> I am a bit worried about that patch as it adds a completely pointless set of
> brackets in a couple of places. If I see
> if (( ... )) {
Err, where do you see pointless brackets? Can you give a precise example?

I have seen this before in the past (and reported to Jim in the libvirt mailing list) and I confirm that I also see it when trying to install and/or run F19.
As already said, what I have in xenstore looks sensible (i.e., not seeing any '-1'), and I'm not using any backported patch, just plain Xen and Libvirt F18 and F19 (I tried both as Dom0, and I'm seeing the issue in both cases) packages.
Dario

Oh, and BTW, nor adding '-x vnc' neither something like '--graphics vnc,listex=xxx' seem to do any magic here... I tried both and I'm still seeing the very same black screen with only 'serial0' on it that Konrad posted

(In reply to Jim Fehlig from comment #7)
> Created attachment 765282[details]
> backport of commit 5420f265
>
> I've been using this backport with 4.2.x for some time now and have not
> noticed any issues.
That patch fixes the issues I saw. With it the FB shows the guest.

(In reply to Konrad Rzeszutek Wilk from comment #1)
> Tried the backport (as suggested by Jim) but no luck
Looking back at my specfile, I added the patch in the spec file:
Patch95: bz977987
but I forgot the patch stanza: %patch95.
So I actually never tested the patch until today :-(

Package xen-4.2.2-10.fc19:
* should fix your issue,
* was pushed to the Fedora 19 testing repository,
* should be available at your local mirror within two days.
Update it with:
# su -c 'yum update --enablerepo=updates-testing xen-4.2.2-10.fc19'
as soon as you are able to.
Please go to the following url:
https://admin.fedoraproject.org/updates/FEDORA-2013-11837/xen-4.2.2-10.fc19
then log in and leave karma (feedback).